The objective of this study is to identify nutritional risk factors for adult cancers, particularly breast, prostate, and colon. Exposures of primary interest include diet, alcohol ingestion, physical activity, height, weight, and body fat distribution. The relationship between cancer and exposures that may be affected by diet, such as serum lipids and sex hormones, also are of interest. (See related project Z01 CN 00147-09 CPSB). The Framingham Heart Study is an ongoing prospective cohort study that was initiated in 1948 to examine risk factors for coronary heart disease, stroke, and other cardiovascular endpoints. Data on behavioral and physical characteristics of the 5,209 cohort members have been collected at biennial visits (exams) for almost 50 years. In 1985, DCPC funded a contract to procure a file identifying all cancers diagnosed among members of the cohort through exam 18, and in 1994 we funded a second contract to update this file through exam 22. The Framingham Study has been used for prospective cohort studies of alcohol, body fat distribution, physical activity, and serum lipids in relation to cancer. The contract to update the cancer file was completed in December 1996. A manuscript on the relation of bone mass, an indicator of cumulative estrogen exposure, to risk of breast cancer was published in the New England Journal of Medicine. Analysis to evaluate relations of diet to breast cancer risk; height to breast and prostate cancer risk; male pattern baldness, which is related to 5-alpha-reductase activity, to prostate cancer risk; and parental age to prostate cancer risk are underway, and numerous additional analysis are planned.